'55 Chevy truck: nothing vs roll bar vs cage

[6DoF]

So this is my first street machine, and this is my first post here. please bear with me and i would love to have your opinions.



I compete in multiple off road series, and build mainly jeeps, so i am a HUGE fan of a full cage. when i started planning this build, i simply assumed i would be building essentially a full tube chassis car. however the more i thought about what i wanted out of this truck, the more i questioned if it was a good idea. the truck is a 1955 chevy 3800 with a factory 9ft step side box. i will be building a 4-link rear, using C10 IFS, and building my own frame between em. i figure the C10 geometry is an easy inexpensive place to start, i can either buy upgrades later or build my own geometry to replace it if it gets out driven. the truck will be on air and 99% of it's life will be general street use. this will be my daily driver when there is no salt on the road, general hot-rod cruising, and i'm not afraid to use it as a truck or maybe even tow the airstream.

now the actual concern, it is 1955 sheet metal and will be riding low. i drive a good ways in high traffic for work, and i'm not sure i trust the old girl to have my back when a soccer mom drops her coffee and finds the wrong pedal. here's hoping i never have to find out. i know my chassis will be way better then factory, but you can always do more. i am also not one to just build something without class spec considerations. if i am putting in the time, i want it to pass tech if i do get the chance to rag on the truck. there are just so many rule books i can't find em all.

-easy and most clean: nothing
just drive it like it is, still 100x safer than a motorcycle.

-middle ground compromise: roll bar
so the B pillar bar should be pretty easy to install and tie into the chassis. even a decent door bar shouldn't be too hard or in the way. the x bracing within the B will greatly reduce the already very small "cargo" room behind the seats, but i'm not sure this matters when i have a truck bed. speaking of the truck bed, i'm not sure i can bring myself to install the down bars back there for everyday use. are there ANY legal ways to make bolt-in bars? my research suggests not, but i know there are a lot of classes in a lot of sanctioning bodies i don't know about yet. while safer than nothing, if it doesn't fit into any class, i'm not sure it's worth cutting into the back of the cab for.

-all-in: full cage
again, my biggest concern here are the rear down bars into the bed. the A pillar might get tricky to match the trucks, but shouldn't be too bad. also lots of room for a dash bar, i just don't know about the space for getting around a vintage air system on the passenger side to tie in under the hood. seams to me a class that only required a roll bar, might accept a 12pt cage with no rear down bars, but that doesn't seam to be the case.

i'm also looking for anyone with tips/tricks on working inside the '55 cab. i have been able to find a few pictures, but never someone to ask questions. i am open to all questions/comments/criticism, it's why i posted. what would you do?

[mikedc]

Tough questions.


The down-bars into the trunk issue is a messy one. No good solution there unless you start violating various sanctioning body rules for cages. IMO that is probably your only option if you want to come near your goals. The rulebooks & standard advice is well-meaning but it does not make any allowance for the realities of, "this idea isn't up to code but I'm choosing between either this or doing nothing at all." Some oddball ideas can be worse than nothing but others are not.

I would consider a "doubled" main hoop for this job. (Think of the big cosmetic chromed pickup truck bed rollbars with lights on top.) Take two copies of the main hoop and weld them together back-to-back. This would really stiffen the main hoop in the front/back direction. Then you could maybe use rear diagonals mounted partway down on the sides of the main hoop(s) instead of up at the top.



Whatever you do, the right padding is CRUCIAL for this situation. The old school cheap plumping type padding is nearly worthless for your head. Imagine whacking the tube with a baseball bat - you need something that actually feels very hard for a "pad". Ideally of course you'd put a softer layer on top and a harder layer underneath that.

Some people argue that you can't possibly pad a cage well enough to drive the car without a helmet. But following that logic means people should never drive any automobile on the road without a helmet, ever. Many of the modern cars I've been inside have the metal structure of the roof within 3 inches of my head and the headliner only pads it less than an inch from that. These modern rides are deemed safer than old cars with the metal (slightly) farther away but but no padding at all.

[6DoF]

the more i read, i more i realize that less is required then i would have thought. for actual regulations, i see no reason why this truck would ever need a cage, just a bar at best. either way, i'm not sure it's worth the rear bars thru the cab. a solid B-pillar with internal diagonals and good solid door bars that are all tied to the chassis seams like the best plan for the street. the if i ever get into any racing enough that i do need to pass tech, then i can add my rear bars.

i hope to start my build thread this fall, i need to start my CAD work here ASAP.

[RobNoLimit]

There are two main benefits to some type of roll bar or cage. Safety and performance. Our old racer truck, the Silver Bullit F100, was built on one of our Big-10 chassis. Plenty strong and handled great, but I can say, that charging down the back straight at Thunder Hill without a cage does NOT give you the 'warm and fuzzies' in the drivers seat. - Thickness of the door sheet metal aside, the door latch is a piece of crap. A nice cage is not to hard to fit into those cabs. For looks, the rear bars car exit below the bed rail tops, and still be a big help in chassis strength. - I would consider 2nd gen. Camaro ('70-81) front stub to the C10. Much better geometry, lighter, better track width fit, and tons of aftermarket support.

[6DoF]

For looks, the rear bars car exit below the bed rail tops, and still be a big help in chassis strength. - I would consider 2nd gen. Camaro ('70-81) front stub to the C10. Much better geometry, lighter, better track width fit, and tons of aftermarket support.

do you have a picture of what you are talking about for the rear bars?

for the IFS, the major draw for the C10 setup is the 100% bolt-in nature of the cross member and geometry. i can get the truck on the road very easy and very cheap to start with, and with many options for later. if i ever out-drive this setup, i can buy or design/build an entire bolt-in swap.

[HandOverFist]

Per NHRA...you would not like it much in a driver tho.

"Steel-bodied pickup trucks (7.50 seconds and slower), roll cages
are permitted with no back braces if the roll cage satisfies SFI
25.1, 25.2, 25.4, or the roll cage consists of a 4-point (door car)
cage with a complete SFI 2.4, 2.5, 2.6, 2.7 dragster, SFI 10.2,
10.3 altered, or SFI 10.4 street roadster roll cage/driver’s
compartment incorporated into and attached to the 4-point roll
cage. An upper windshield bar is mandatory.
Non-steel-bodied pickup trucks (7.50 seconds and slower), roll
cages are permitted with no back braces if the roll cage
satisfies SFI 25.1, 25.2, 25.4, or the roll cage satisfies the
requirements for SFI 2.4, 2.5, 2.6, 2.7 dragster, SFI 10.2, 10.3
altered, or SFI 10.4 street roadster roll cage/driver’s
compartment. No 4-point (door car) cage is required and no
upper windshield bar is required."